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\03 



A METHOD OF MEASURING FISH EGGS 

By H. von Bayer, C. E. 

Architect and Engineer, United States Bureau of Fisheries 

J- 

Paper presented before the Fourth International Fishery Congress 
held at Washington, U. S. A., September 22 to 26, 1908 

BULLETIN OF THE BUREAU OF FISHERIES : : : : : VOL. XXVIII. P. 1009-1014 
Document No. 703 :::::::::::::::: : : : : Issued April. 1910 



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A METHOD OF MEASURING FISH EGGS. 



By H. VON BAYER, C. E., 
Archilecl and Engineer, United States Bureau oj Fisheries. 



In a well-regulated fish hatchery it becomes at times necessary to count 
the eggs of fishes, so as to know the quantity on hand and prepare for certain 
shipments of eggs as well as for the future care of the fry. The methods thus 




Fig. I . — Metal trough for use in determining diameter of fish eggs. 



far employed have been to determine by actual count the number of eggs con- 
tained in one liquid quart measure, and then to multiply said number by the 
number of quarts of eggs on hand ; or to weigh one liquid quart of counted eggs, 
next to weigh all the eggs on hand, and then by simple proportion to determine 
the number of all the eggs. 

The new method proposed by the writer is first to determine the diameter ° 
of one egg, and then to enter with the value of said diameter a table or diagram 

a By diameter is here understood the diameter of the egg including its surrounding matrix, if any. 

lOII 



IOI2 BULLETIN OF THE BUREAU OF FISHERIES. 

in which the corresponding number of eggs per Uquid quart or other unit 

measure is found by inspection. 

To determine the diameter of one egg of a certain species of fish, a V- 

shaped metal trough with scale engraved thereon is used, in which a certain 

number of eggs is placed one egg deep in a row, the eggs touching each other; 

the space occupied by the eggs is then read on the scale; this reading, when 

divided by the number of eggs in the trough, will give the diameter of one egg. 

The accompanying table and diagram are self-explaining. They are based 

on a series of actual counts of eggs contained in a liquid quart measure, these 

counts fairly agreeing with each other and the theoretical value, and being 

extended by computation according to the law that solids increase as the third 

power of their diameters. 

Example : 

d =0.127", diameter of whitefish egg (determined). 

n =33,036, number of whitefish eggs per quart (actually counted). 

di =0.1406", diameter of shad egg (determined). 

Ui = Number of shad eggs per quart (sought) . 

d' : di^ = n, : n 

d^'n 
.•.n, = ^,or 

0.127' : 0.1406' = ni : 33,036 
„ 0.127^X33,036 



0.1406' 



= 24,345, answer. 



METHOD OF MEASURING FISH EGGS. IOI3 

Table for Finding Number of Fish Eggs op Given Diameter per Liquid Quart. 



Diame- 
ter. 


Number. 


Diame- 
ter. 


Number. 


Diame- 
ter. 


Number. 


Diame- 
ter. 


Number. 


Inch. 




Inch. 




Inch. 




Inch. 




0.300 


2.S06 


0.230 


5. 562 


0. i6o 


16.521 


0. 090 


92.826 




2.S3I 




5.635 




16,83s 




95.990 




2.SS7 




5. 709 




17, 157 




99. 297 




2.583 




S.78S 




17.487 




102,762 




2. 609 




5. 862 




17.825 




106, 390 


0. 295 


2.635 


0.22s 


5.941 


0. ISS 


.8.172 


0.08s 


no, 190 




= .663 




6.021 




18,528 




114, 172 




2. 690 




6. 102 




18.894 




118,346 




2.718 




6.18s 




19. 270 




122, 730 




2. 746 




6. 269 


0. isi 


19.65s 




127,333 


0. 290 


2. 775 




6,3SS 


0. ISO 


20.050 


0,080 


132, 170 




2,804 




6, 442 




20.456 




137. 251 




2.833 




6,531 




20.874 




142, 600 




2,863 




6,622 




21.303 




148.220 




2,893 




6,71s 




21.744 




154. 155 


0.28s 


2,923 


0. 215 


6,809 


0. 145 


22, 197 


0.07S 


160, 400 




2.954 




6,90s 




22,662 




166,995 




2.985 




7,002 




23, 140 




173,950 




3.017 


1 


7. 102 




23,633 




181,300 




3.050 


1 


7. 204 




24, 140 




189,070 


0. 280 


3.083 


1 0. 210 


7.307 


0. 140 


24.661 


0.070 


197, 290 




3. 116 




7.412 




25.197 




205,992 




3, 150 




7.S20 




25.748 




215, 204 




3, 184 




7.629 




26.316 




224,995 




3,219 




7. 74t 




26.901 




235,377 


0.275 


3. 254 


0. 205 


7.855 


o. 135 


27. S04 


0. 065 


246,410 




3. 290 




7.971 




28.125 




258,141 




3.326 




8.089 




28.764 




270.631 




3,363 




8,210 




29. 422 




283,936 




3,400 


0. 2or 


8.333 




30, loi 




298.132 


0.270 


3,438 


0. 200 


8.459 


0. 130 


30,801 


0.060 


313.289 




3,476 




8.S87 




31,523 




329,490 




3.51S 




8.717 




32.268 




346.828 




3,SSS 




8.851 




33,036 




365,405 




3. 595 




8.987 




33.829 




385,331 


0.26s 


3.636 


o. I9S 


9,126 


0, 125 


34. 647 


0.05s 


406. 733 




3.677 




9, 268 




35.492 




429, 750 




3.719 




9,413 




36.364 




454. 539 




3.762 




9. S6l 




37. 26s 




481.270 




3,806 




9. 712 




38, 198 




510, 139 


0. 260 


3.850 


0. 190 


9.866 


0. 120 


39, 161 


0.050 


541,362 




3.89s 




10.023 




40, 156 




575, 173 




3.940 




10,184 




41,186 




611,893 




3.986 




10,348 




42. 251 




651. 776 




4.033 




io,si6 




43,354 




69s. 223 


0. 2S5 


4.081 


0.18s 


10.688 


0. IIS 


44. 494 


O.04S 


742,613 




4. 129 




10.863 




45.676 




794. 400 




4,178 




11.042 




46.899 




851. 128 




4,228 




11.225 




48, 166 




913.380 


0. 251 


4.279 




II, 412 




49.480 




981.852 


0.250 


4.331 


0.180 


II, 603 


0. no 


SO. 841 


0.040 


1.057.350 




4.383 




II. 799 




52. 254 




I. 140, 780 




4, 436 




11.999 




53. 720 




1.233, 250 




4, 490 




12. 203 




55. 239 




I. 335. 960 




4,545 




12, 412 




56,817 




I. 450, 406 


0. 24s 


4, 601 


0. 17s 


12,627 


0. los 


58.456 


0.035 


1.578.320 




4.658 




12,846 




60. 159 




1.721,630 




4.716 




13.069 




61,925 




1.883.020 




4. 776 




13.298 




63,766 




2,065, 130 




4.83s 




13.533 


0. lol 


65,680 




2. 271,500 


0.240 


4.895 
4.956 
5.019 
5.083 
5, 148 


0. 170 


13.774 
14,020 
14, 272 
14.529 
14, 793 




67, 670 
69. 741 
71.899 
74, 146 
76. 486 


0.030 


2,506,310 


0. 23s 


III'. 
5. 350 
5. 419 
5.490 


0.16s 


IS. 064 
IS. 341 
15,625 
15.916 
16. 215 


0.095 


78,927 
81,473 
84,130 
86. 904 
89, 800 







CON\'ERSION TABLE. 



inch 




4 millimeters. 


millimeter 




03937 inch. 


quart 


= S7 


75 cubic inches. 


quart 




9464 liter. 


liter 


-61 


0234 cubic inches 



I liter = 1.0567 quarts. 

I pound = 0.4536 kilogram. 
I kilogram = 3.2046 pounds. 
Fahrenheit =9/5 centigrade ± 3 2 ' 
Centigrade =5/9 Fahrenheit ±32 



IOI4 



BULLETIN OF THE BUREAU OF FISHERIES. 



O/O/H. IM 

cftclmoU 
ofairlneh 



Portion of O/a^ram shoir/n^ method of 
findincf number of eqys per //quid ^uart 




10,000 toiooo 3opoo Acooo 501,000 



70)000 60,000 90000 loqpoo 



Directions: Find the line on the left margin corresponding to the given diameter; follow said line to 
the right until it intersects the curve; from this intersection proceed at right angles to the lower mar- 
ginal line of figures and there read the required number of eggs per quart. 

If diameter is given in millimeters multiply by 0.03937 to reduce to inches. 



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